Correlation between daily exercise load and physical fitness among primary school students / 中国学校卫生

Objective@#To understand the relationship between daily exercise load and physical fitness of primary school students, so as to provide relevant theoretical basis for the development of on campus physical education plans and the improvement of procedural physical health management for elementary school students.@*Methods@#A total of 223 students from 6 classes in a primary school in Beijing were selected by a stratified random cluster sampling method from May to June 2023. The daily exercise load of the students was monitored by Polar Verity Sense heart rate armband. The duration of moderate to vigorous physical activity (MVPA) and daily Training Impulse (TRIMP) value were calculated, and the related indexes of daily exercise load were analyzed. Chi square test and univariate Logistic regression analysis were used to analyze the correlation between daily exercise load and physical fitness assessment levels, and multi factor ordinal Logistic regression analysis was used to explore the influencing factors of physical fitness assessment levels.@*Results@#The average time spent in MVPA was (21.65±17.48) min. The TRIMP value was (361.47±124.81). The time spent in MVPA of primary school students in outdoor class, zero point sports, recess and after class PE were ( 8.86 ±8.56, 9.41±10.47, 1.97±3.12, 2.46±2.57) min, respectively. TRIMP values were (68.89±20.84, 72.83±30.27, 51.68±18.23, 19.99±5.78) in outdoor class, zero point sports, recess and after class PE, respectively. The results of univariate analysis showed that there were statistically significant differences in physical fitness levels among students with different genders, grades, and BMI ( χ 2=7.13, 19.04, 32.98, P <0.05). The duration of daily MVPA, along with TRIMP value during outdoor class, zero point sports, recess, and after PE class were all statistically significant with physical fitness levels ( OR =1.07, 1.05, 1.02, 1.03, 1.11, P <0.05). The results of multi factor ordinal Logistic regression analysis showed that the primary school grade (lower grade: OR =9.24, middle grade: OR =7.81), BMI (abnormal: OR =0.21), duration of daily MVPA in school ( OR =1.06), and TRIMP value during outdoor class ( OR =1.05) were statistically significant with physical fitness levels ( P <0.05).@*Conclusions@#There is a positive correlation between physical fitness and different grades, BMI, daily exercise load, and outdoor exercise load. Increasing daily exercise load can improve students physical health. It is suggested to tailor the school sports program to suit primary school students, increase both the intensity and duration of school daily sports, and promote procedural physical health management for elementary school students.

The characteristics of daily exercise load of students of different grades in a primary school in Beijing / 中国学校卫生

Objective@#To analyze the characteristics of the daily exercise load and the One Hour of Moderate to Vigorous Physical Activity (MVPA) per day among primary school students, so as to provide a reference for improving the quality of the physical activity of primary school students in school.@*Methods@#A total of 223 students from an elementary school in Beijing from May to June of 2023, were selected by stratified random cluster sampling method. The Polar Verity Sense heart rate arm band was used to monitor and evaluate the daily exercise load heart rate according to different grades, gender and physical quality.@*Results@#The average heart rate of primary school students in outdoor class, zero point sports, recess and indoor class was (130.01±13.11, 119.89± 16.02,109.96±8.11,96.81±7.89) times/min, respectively, and only 4.04% students met the standard of 1 hour MVPA daily. From the perspective of different grades, the MVPA time ratio of lower grade students in outdoor class, zero point sports and big break was 28.41%, 42.47% and 8.24%, that of middle grade students was 18.33%, 6.41% and 5.90%, and that of senior students was 45.91%, 3.88% and 11.43%. The number of students who achieved 1 hour daily MVPA was 5.41%, 0 and 6.67%. Time ratio of MVPA in outdoor classes, zero hour sports and big breaks accounted for 30.09%, 16.34% and 9.23% for boys, 31.70%, 16.24 % and 6.13% for girls, and the interval distribution of boys and girls who achieved MVPA for one hour per day was 5.88% and 2.86%.Time ratio of MVPA for students with excellent physical fitness were 33.19%, 21.76% and 8.25% in outdoor class, zero point sports and big break, while those with good physical fitness were 29.76%, 12.93% and 8.19%.A total of 21.78%, 5.99% and 4.80% of the students passed the physical fitness test, and the number of students with excellent, good and passed the physical fitness test who achieved the daily 1 hour MVPA was 5.88%, 3.77% and 0.@*Conclusion@#In the present study, elementary and middle school students time for in school physical activity was adequate, but there are problems of low loading intensity and insufficient time for MVPA. It is necessary to arrange targeted physical activity programs for students of different grades, genders and physical fitness levels to increase the daily exercise load of students in school.

Analysis of exercise density and exercise load in different physical classes for second year junior high school students from Beijing City / 中国学校卫生

Objective@#To explore the exercise intensity and effective exercise load of different physical fitness classes for second year junior high school students in Beijing, so as to provide a reference for optimizing the teaching content of physical fitness classes, reasonably regulating exercise load and the scientific development of physical fitness.@*Methods@#From October to November 2022, 30 second year junior high school students from a middle school in Xicheng District, Beijing were selected to have their heart rate monitored during physical fitness classes using Polar heart rate monitors. Heart rate intervals and training impulse (TRIMP) were used to quantify exercise intensity and load. Independent sample t-test was used to statistically analyze differences in heart rate across different dimensions.@*Results@#The average heart rate of students in physical fitness classes was (140.62±9.41) counts/min, with effective exercise load (heart rates ≥120 counts/min) time accounting for 77.2%, and heart rate load of moderate to vigorous physical activity (MVPA) time accounting for 51.9%. The average heart rates for speed, speed endurance, and endurance physical fitness classes were (137.89±8.82) (137.67±11.27) and (145.35±8.98) counts/min, respectively. The average heart rates of male and female students in physical education class were (144.22±24.95) and (136.31±28.78) counts/min, and the difference was not statistically significant ( t=4.04, P >0.05). The cumulative durations of effective exercise load among male and female students were (34.08± 7.52 ) and ( 28.43 ±5.39) min, respectively. The average TRIMP value for physical fitness classes were (100.46±16.56), with a exercise density of 72.06%.@*Conclusions@#The exercise intensity of physical fitness classes for secondyear junior high school students in Beijing is appropriate, mainly with moderate to vigorous intensity, and the accumulated time of MVPA is sufficient. The average heart rate and exercise density of students meet the requirements. Scientific setting of physical fitness class exercise load should be based on individual differences in students physical fitness, in order to improve the physical health level of middle school students.

Experimental study on PE sport load evaluation of primary school students based on heart rate interval and training impulse / 中国学校卫生

Objective@#To explore the PE sport load and its influencing factors of primary school students and to provide the basis for scientific and reasonable arrangement of PE sport load and increase its exercise effect.@*Methods@#A total of 208 students from grade 5 and grade 6 of Small Wild Goose Pagoda Primary School in Xi an were selected. Stopwatch and PolarOH1 photosensitive heart rate sensor were used to record the time of each PE lesson, the students practice time and the continuous heart rate of the students during PE lesson. The exercise intensity and sport load of PE lesson were calculated by heart rate interval and training impulse (TRIMP) to evaluate the scientific nature and effectiveness of physical education.@*Results@#The average continuous heart rate was (132.5±15.2)time per min. The primary school students PE classes were mainly of low moderate intensity, and moderate to vigorous physical activity (MVPA) accounted for 36.7% of the total class time.The average TRIMP of PE was (76.62±26.69). The average exercise density was 53.6%, and the average time of preparation, basic and end parts was 13.32, 25.57 and 0.50 min, respectively.@*Conclusion@#The PE intensity and TRIMP of primary school students are too small, the cumulative time of MVPA is insufficient, the PE exercise density is appropriate, the preparation part is too long, and the end part is too short. Therefore, the PE exercise load should be strengthened to improve the sports quality of PE students.

Oral exposure to lead for Japanese children and pregnant women, estimated using duplicate food portions and house dust analyses

BACKGROUND@#Lead is a toxic metal abundant in the environment. Consumption of food contaminated at low levels of lead, especially by small children and pregnant women, raises a health concern.@*METHODS@#Duplicated food portions and drinking water were collected over 3 days from 88 children and 87 pregnant women in Shimotsuke, Tochigi, Japan. Participants were recruited in this study between January 2014 and October 2015. Dust was also collected from their homes. Lead concentrations were measured and consequent oral lead exposure levels were estimated for this population at high risk to environmental toxicants. Lead concentrations of peripheral and cord blood, taken from children and pregnant women, and were also analyzed.@*RESULTS@#Lead concentrations in food, drinking water, and house dust were low in general. Oral lead exposure to lead was higher for children (Mean ± SEM; 5.21 ± 0.30 μg/kg BW/week) than in pregnant women (1.47 ± 0.13 μg/kg BW/week). Food and house dust were main sources of lead contamination, but the contribution of house dust widely varied. Means ± SEM of peripheral and cord blood lead concentrations were 0.69 ± 0.04 μg/dL and 0.54 ± 0.05 μg/dL, respectively for pregnant women and 1.30 ± 0.07 μg/dL (peripheral only) in children. We detect no correlation between smoking situations and blood lead concentration in pregnant women.@*CONCLUSION@#We conclude that oral lead exposure levels for Japanese children and pregnant women were generally low, with higher concentrations and exposure for children than for pregnant women. More efforts are necessary to clarify the sources of lead contamination and reduce lead exposure of the population at high risk even in Japan.

Physiological load of physical education class of high schools in Xicheng District of Beijing / 中国学校卫生

Objective@#To evaluate physical load of different sports and in various forms of physical education class.@*Methods@#117 healthy adolescents (57 girls and 60 boys) were recruited from 6 high schools in Xicheng District of Beijing (2 high schools of type 1, 2 of type 2, and 2 of type 3), and each 10 students were randomly selected from grade 1 and 2 in the high school. Polar Team 2 was used to measure physiological load in martial arts, throwing, jumping and basketball, and 639 persontime eligible data were collected.@*Result@#In martial arts and high jump class, duration of heart rate response (HRmax) below 60% in the new classes were significantly longer, while duration of moderatetovigorous physical activity (MVPA) was shorter than comprehensive courses and review courses(P<0.05). Students spent about an average of 24.6 (9-34) minutes in activities of HRmax below 60% in P.E.class, accounting for 54.7% of P.E. class time, an average of 17.3 (7-26) minutes in activities of HRmax between 60%-80%, accounting for 38.4% of P.E. class time, and an average of 3.5 (0-20) minutes in activities of HRmax higher than 80%, accounting for 6.9% of P. E. class time.@*Conclusion@#This physical load cannot achieve the goal of improving adolescents’ physical fitness. Government should strengthen the continuing education of PE teachers and update their knowledge constantly, in order to maximize the physical education benefit for adolescents.

Incidence and cost estimate of treating pediatric adverse drug reactions in Lagos, Nigeria / Incidência e estimativa de custo do tratamento de reações adversas a drogas de uso pediátrico em Lagos, Nigéria

CONTEXT AND OBJECTIVES: Adverse drug reactions (ADRs) may cause prolonged hospital admissions with high treatment costs. The burden of ADRs in children has never been evaluated in Nigeria. The incidence of pediatric ADRs and the estimated cost of treatment over an 18-month period were determined in this study. DESIGN AND SETTING: Prospective observational study on children admitted to the pediatric wards of the Lagos State University Teaching Hospital (LASUTH) in Nigeria, between July 2006 and December 2007. METHODS: Each patient was assessed for ADRs throughout admission. Medical and non-medical costs to the hospital and patient were estimated for each ADR by reviewing the medical and pharmacy bills, medical charts and diagnostic request forms and by interviewing the parents. Cost estimates were performed in 2007 naira (Nigeria currency) from the perspectives of the hospital (government), service users (patients) and society (bearers of the total costs attributable to treating ADRs). The total estimated cost was expressed in 2007 United States dollars (USD). RESULTS: Two thousand and four children were admitted during the study; 12 (0.6 percent) were admitted because of ADRs and 23 (1.2 percent) developed ADR(s) during admission. Forty ADRs were suspected in these 35 patients and involved 53 medicines. Antibiotics (50 percent) were the most suspected medicines. Approximately 1.83 million naira (USD 15,466.60) was expended to manage all the patients admitted due to ADRs. CONCLUSIONS: Treating pediatric ADRs was very expensive. Pediatric drug use policies in Nigeria need to be reviewed so as to discourage self-medication, polypharmacy prescription and sales of prescription medicines without prescription.

CONTEXTO E OBJETIVOS: Reações adversas a drogas (RAD) podem causar hospitalização prolongada com alto custo de tratamento. Este efeito das RAD em crianças nunca foi avaliado na Nigéria. A incidência de RAD em pediatria e o custo estimado de tratamento em um período de 18 meses foram determinadas neste estudo. DESENHO E LOCAL: Estudo prospectivo observacional de crianças admitidas nas unidades pediátricas do Hospital Universitário do Estado de Lagos (LASUTH) na Nigéria, entre julho de 2006 e dezembro de 2007. MÉTODOS: Cada paciente foi avaliado para RAD durante a admissão. Os custos médicos e não médicos para o hospital e para o paciente foram estimados para cada RAD pela revisão das contas médicas e da farmácia, pelos registros médicos, pelos exames necessários para diagnóstico e pelas entrevistas com os pais. Os custos foram estimados em nairas (moeda nigeriana) de 2007 a partir das perspectivas do hospital (governo), dos usuários de serviços (pacientes) e da sociedade (portadores dos custos totais atribuídos ao tratamento de RAD). A estimativa de custo total foi apresentada em dólares americanos (US) de 2007. RESULTADOS: Duas mil e quatro crianças foram admitidas durante este estudo; 12 (0,6 por cento) foram admitidas devido a RAD e 23 (1.2 por cento) desenvolveram RAD durante admissão. Quarenta RAD foram suspeitadas nesses 35 pacientes e envolveram 53 medicamentos. Antibióticos (50 por cento) foram as drogas mais suspeitas. Aproximadamente 1.83 milhões de nairas (US 15,466.60) foram gastos para cuidar de todos os pacientes admitidos por RAD. CONCLUSÕES: O tratamento das RAD pediátricas foi bastante caro. As políticas de uso de drogas em pediatria na Nigéria devem ser revistas para desencorajar a auto-medicação, a prescrição de polifarmácia e a venda de medicamentos de prescrição sem prescrição.

Effect of Cumulative Blood Lead and Cumulative Blood ZPP as Lead Body Burden on Renal Lead Biomarkers / 대한산업의학회지

OBJECTIVE: To evaluate the possibility of cumulative blood lead and blood ZPP as surrogates of lead body burden and to investigate their association with renal function as an index of lead body burden. METHODS: The study subjects comprised 678 lead workers with past blood lead and blood ZPP data from their employment. Cumulative blood and ZPP were calculated by accumulating the every year mean value of both indices from the new employment since 1983. To assess the cumulative data of lead workers who started their lead work before 1983, the years before 1983 were simulated with the first available data from 1983. Study variables for lead body burden were tibia bone lead and DMSA chelatable lead, whereas those for current lead biomarkers were blood lead and blood ZPP. BUN and serum creatinine were selected as clinical renal biomarkers, while NAG (N-acetyl-D-glucosamine) and RBP (Retinol binding protein) were selected as early renal biomarkers. RESULTS: The association between cumulative blood lead and blood ZPP with tibia bone lead was statistically significant with determinant coefficients (r(2)) of 0.72 and 0.567, respectively, and their relationships were better explained by the curvilinear regression model. In multiple regression analysis of current lead biomarkers on the renal biomarkers after controlling for possible confounders (age, sex, job duration, smoking and drinking status), blood lead was associated only with log-transformed NAG, whereas blood ZPP was associated with 3 other renal biomarkers. On the other hand, in multiple regression analysis of biomarkers of lead body burden on renal biomarkers after controlling for possible confounders (age, sex, job duration, smoking and drinking status), cumulative blood ZPP and tibia bone lead were associated with all 4 renal function biomarkers, whereas cumulative blood lead and DMSA chelatable lead were associated with 3 renal biomarkers except BUN. CONCLUSION: Cumulative blood and ZPP were demonstrated to be good surrogates of lead burden. Furthermore, the cumulative blood ZPP was confirmed to have a better association than the cumulative blood lead.

Maternal Exposure to 2,3,7,8-Tetrachlorodibenzo-\it{p}-Dioxin and the Body Burden in Offspring of Long-Evans Rats

Objectives: In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) results in a wide variety of developmental effects in pups at doses much lower than those causing overt toxicity in adult animals. We investigated the relationship between tissue concentrations of TCDD in dams and fetuses and developmental effects on pups. Materials and Methods: Pregnant Long-Evans rats were given TCDD at a single oral dose of 12.5, 50, 200, or 800 ng of TCDD or [3H]-TCDD/kg bw on gestation day (GD) 15. Dams were sacrificed on GD16 and GD21, and the tissue concentrations of TCDD were measured in dams and fetuses. Pups were sacrificed on postnatal day (PND) 49 and PND63 for males and PND70 for females, and the reproductive effects and tissue concentrations of TCDD were determined. Results: The sex ratio (male/female) on GD21 was significantly reduced at 50 ng TCDD/kg and at 12.5 and 50 ng TCDD/kg at birth, but not at other doses. Delayed puberty was observed in males at 200 ng TCDD/kg and in males and females at 800 ng TCDD/kg. Anogenital distance, testis weight, epididymal sperm count, sperm motility, and ejaculated sperm count were not affected. Estrous cyclicity was not different from that of the control in any treatment group. A dose-dependent decrease in weight of seminal vesicle and prostate on PND49 was observed. Prostate weight was significantly decreased at 800 ng TCDD/kg. At this dose, maternal body burden and TCDD concentration in fetuses were 290 pg TCDD/g and 52 pg TCDD/g on GD16, respectively. Reduced prostate weight is a sensitive and commonly observed endpoint so that the body burdens of dams and fetuses at the LOAEL of this endpoint could be served as the basis for establishing TDI for dioxins.

Maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin and the body burden in offspring of long-evans rats

<p><b>OBJECTIVES</b>In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) results in a wide variety of developmental effects in pups at doses much lower than those causing overt toxicity in adult animals. We investigated the relationship between tissue concentrations of TCDD in dams and fetuses and developmental effects on pups.</p><p><b>MATERIALS AND METHODS</b>Pregnant Long-Evans rats were given TCDD at a single oral dose of 12.5, 50, 200, or 800 ng of TCDD or [(3)H]-TCDD/kg bw on gestation day (GD) 15. Dams were sacrificed on GD16 and GD21, and the tissue concentrations of TCDD were measured in dams and fetuses. Pups were sacrificed on postnatal day (PND) 49 and PND63 for males and PND70 for females, and the reproductive effects and tissue concentrations of TCDD were determined.</p><p><b>RESULTS</b>The sex ratio (male/female) on GD21 was significantly reduced at 50 ng TCDD/kg and at 12.5 and 50 ng TCDD/kg at birth, but not at other doses. Delayed puberty was observed in males at 200 ng TCDD/kg and in males and females at 800 ng TCDD/kg. Anogenital distance, testis weight, epididymal sperm count, sperm motility, and ejaculated sperm count were not affected. Estrous cyclicity was not different from that of the control in any treatment group. A dose-dependent decrease in weight of seminal vesicle and prostate on PND49 was observed. Prostate weight was significantly decreased at 800 ng TCDD/kg. At this dose, maternal body burden and TCDD concentration in fetuses were 290 pg TCDD/g and 52 pg TCDD/g on GD16, respectively. Reduced prostate weight is a sensitive and commonly observed endpoint so that the body burdens of dams and fetuses at the LOAEL of this endpoint could be served as the basis for establishing TDI for dioxins.</p>

Reference Values of Cadmium in Kidney and Liver in Korean / 대한산업의학회지

OBJECTIVES: Cadmium (Cd), a toxic and non-essential metal, is recognized as a human carcinogen, which has a tendency to accumulate in the human body. The levels of Cd in renal cortex and liver are good indicators as an index of Cd exposure in the general population. In this study, we present an estimation of reference Cd levels in tissue (renal cortex and liver) and total body burden in the general population of Korea. MEDTHODS: Cd and zinc (Zn) were analyzed in renal cortex and liver from 254 autopsies (male : 188 cases, female : 66 cases) aged 0 to 87 years. RESULTS: Geometric mean concentration of Cd was 27.4 and 3.1 ua/g wet weight in renal cortex and liver, respectively. The level of Zn in renal cortex and liver was 35.4 and 42. 6 v/g wet weight, respectively. The result suggests that kidney is the target organ for Cd accumulation. The accumulation of Cd in renal cortex was age-dependent with a biphasic pattern. The level of Cd in renal cortex increased with age up to the fifties, and then leveled off thereafter. Based on the data, the regression model for Cd accumulation in renal cortex by age is predicted by : Log KCd = 0. 2325 + 0. 0553 Age 0. 0005 Age. The highest Cd accumulation in renal cortex of Koreans was estimated at 43. 3 ua/g wet weight at 50. 8 years old. In addition, the total Cd body burden by age was estimated by the following equation: Total Cd Body Burden = -4. 5948 + l. 2278 Age - 0. 0121 Age. The highest body burden of Cd was estimated at 26. 5 mg at age 50. 7 years in the Korean general population. The positive correlation between Zn and Cd was observed in renal cortex and liver. CONCLUSIONS: The level of Cd exposure in Korean was found to be lower than in Japanese, but same as or higher than in American and Europeans.